How to Grow and Care for Purple Fountain Grass

Growing purple fountain grass is easy. Although it can be planted nearly anytime, spring is the most suitable time for planting. These plants need to be placed in a sunny location with well-draining soil.

Growing Purple Fountain Grass – How To Take Care Of Purple Fountain Grass

Of all the ornamental grasses, of which there are many, purple fountain grass (Pennisetum setaceum ‘Rubrum’) is probably one of the most popular. The purple or burgundy-colored foliage and soft, fuzzy-like blooms (which are followed by purplish seedheads) make a bold statement in the garden—on their own or grouped with other plantings. Growing purple fountain grass is easy and requires little maintenance once established.

About Purple Fountain Grass

While purple fountain grass is known as a perennial, it is actually considered a tender perennial. This ornamental grass cannot survive cold winters and is hardy only in USDA Plant Hardiness Zones 9 and warmer (though in Zones 7-8 it can sometimes reappear given adequate winter protection). Therefore, it is important that this be a consideration prior to planting purple fountain grass, as the likelihood of its return each year in zones 6 or lower is slim to none. In fact, in cooler regions the plant is normally treated as an annual instead.

However, it is still possible to enjoy this plant year after year when grown in a container and brought indoors for overwintering. You can cut it back to about three inches (8 cm.) or so and then place it either in a sunny window in a cool area of the home or simply place it in your basement. Keep the plant moist, not soggy, watering it about once a month. Once the threat of freezing weather and frost has passed in spring, you can set the purple fountain grass back outdoors.

Grow Purple Fountain Grass

Growing purple fountain grass is easy. Although it can be planted nearly anytime, spring is the most suitable time for planting. These plants need to be placed in a sunny location with well-draining soil.

Since mature plants can reach about four feet tall (1 m.) and just as wide, they should be given plenty of room in the garden, spacing additional plants at least three to five feet (1-1.5 m.) apart. Dig a hole both deep and wide enough to accommodate the roots and then water your purple fountain grass thoroughly.

Take Care of Purple Fountain Grass

Caring for purple fountain grass is also easy. The plant is drought tolerant so watering sufficiently every week or two should be adequate.

Although not required, you can give it an annual feeding with a slow-release, balanced fertilizer in spring to help stimulate new growth.

You should also cut it back in fall prior to bringing the plant indoors or in late winter/early spring for those left outdoors in suitable climates.

How to Grow and Care for Purple Fountain Grass

David Beaulieu is a landscaping expert and plant photographer, with 20 years of experience.

Kathleen Miller is a highly-regarded Master Gardener and horticulturist with over 30 years of experience in organic gardening, farming, and landscape design. She founded Gaia’s Farm and Gardens, a working sustainable permaculture farm, and writes for Gaia Grows, a local newspaper column.

Purple fountain grass is aptly named for the arcing spikes of nodding purplish flowers that gracefully spray out of its mass of long, slender, burgundy-colored leaves. It has a fast growth rate and is best planted in spring. The autumn seed heads of this plant are very attractive and preferred in fall flower gardens. This grass produces flowering stems, which are full of feathery seeds. The feathery seed heads (or “plumes”) can also later be cut for dried flower arrangements.

Light

Purple fountain grass will tolerate some light shade, but it prefers to be planted in full sunlight. Look for an area in your garden where it will receive bright light at least six to eight hours a day.

Soil

Luckily, purple fountain grass isn’t too picky about its soil conditions. Loamy soil often provides the best results, but the plant can do well in many types of mixtures, so long as they’re well-draining.

Water

While purple fountain grass is considered a drought-tolerant ornamental grass, it should still be watered consistently as it’s getting established in your landscape. Give new plants water once or twice a week, about an inch total, allowing time for the soil to dry to the touch between each watering. In areas that receive rain occasionally, you will not need to water the grass once it has become established—areas that are particularly dry or hot may need occasional watering.

Temperature and Humidity

One of the perks of purple fountain grass is just how versatile it is when it comes to temperature conditions. It’s cold-weather hardy down to about 20 degrees Fahrenheit, so if your area remains about that temperature, then you can grow the grass as a perennial and cut it back in early spring each year. New growth will initiate as the temperatures begin to climb.

Meanwhile, those in colder zones will have to make do with enjoying purple fountain grass’s vivid color and striking, vase-shaped form throughout the late spring, summer, and fall—unless they don’t mind going through the trouble of overwintering it indoors. Additionally, the grass has no special humidity needs.

Fertilizer

Fountain grass grows fairly well in poor soil, but fertilizer will boost its growth and provide the additional nutrients it needs when flowering. During that time (typically the summer), feed it monthly with a general-purpose, slow-release food according to the directions on the fertilizer’s label.

Types of Purple Fountain Grass

• Pennisetum setaceum ‘Fireworks’: Another popular cultivar of the purple fountain grass species, this plant has variegated leaves with burgundy in the middle and hot pink at the edges.
• P. alopecuroides ‘Burgundy Bunny’: A cultivar of a relatively cold-hardy species of fountain grass in the Pennisetum genus, this variety stands 16 inches tall. The foliage has hints of red in summer, but the color intensifies to a deep reddish-purple in fall.
• P. alopecuroides ‘Little Bunny’: Another cultivar of P. alopecuroides, ‘Little Bunny’ stands 12 inches tall with a slightly greater spread. This variety lacks the colorful foliage of burgundy bunny but features buff-colored flowers.

Pruning

The standard way to prune ornamental grasses, like purple fountain grass, is to cut it back severely in late winter or early spring before it begins its new growth. This eliminates dead foliage and improves air circulation and sun exposure to stimulate the growth of new leaves. You can also selectively trim dead foliage and perform some light shaping on the plant any time of the year.

To cut back the grass in the spring, gather the leaves of each plant, and bind them with a rope, masking tape, or bungee cord. Use pruners or a scythe to cut the leaves straight across, 4 to 6 inches up from the base of the plant. Comb through the trimmed leaves by hand to remove any additional dead blades and debris.

Propagating Purple Fountain Grass

Purple fountain grass can be propagated through division or seeds. The plants may readily self-seed in the garden, but root division is a faster and more reliable form of propagation than waiting for seeds. Division should be done in the fall after flowering when the plant is going into dormancy. Take these steps for propagating by division:

1. Dig up the plant when it is going dormant.
2. Use a clean, sharp cutting tool to cut it into two or more sections that contain healthy roots and leaves.
3. Discard any rotten or dead plant matter and roots.
4. Replant immediately and keep the soil moist as the division settles into its new home.

How to Grow Purple Fountain Grass From Seed

It’s easy to plant purple fountain grass from seed though it takes time to see results. Collect the seeds from the flowering stems when they’re dry, usually in the fall. Then take these steps to grow the grass from seeds:

1. Take the whole stem and allow the flower stalk to dry out in a cool place.
2. Surface sow the seeds in good potting soil with just a dusting of sand on top.
3. Water until the container is evenly moist.
4. Place the pot in a plastic bag or cover it with a plastic dome. Cut a couple of small slits on top of the bag so seeds can breathe.
5. Once you have seedlings with two sets of true leaves, transplant them to larger pots.
6. Harden off the plants in the spring and install them in prepared containers or beds.

Overwintering

You can dig up the grass and place it in any type of planting container and bring it inside during the winter to survive. Cut the plants down to 3 inches tall.. They won’t look ornamental over the winter, but they should come back in the spring.

Place the container in a cool area or room where the temperature will not reach freezing. The plant’s shallow roots won’t tolerate freezing temperatures. Also, offer the plants a moderate amount of light during the winter. Keep the them watered, but not soggy, and do not let them dry out. Once the weather turns warmer in the spring, take a week to acclimate the plant by bringing it outdoors for a while during the day and indoors at night.

Common Pests and Plant Diseases

The good news is that the rugged purple fountain grass is pretty resistant to pests and diseases. That being said, there are a few more common issues you should keep an eye out for when planting this ornamental in your landscape.

You may notice slugs and snails around your grass, but don’t stress—while they may occasionally eat the foliage, they’re unlikely to cause serious, long-lasting damage.

Rust fungus can commonly occur with purple fountain grass because of trapped moisture or humidity between the dense clumps. Make sure to place your plants several feet apart from one another to increase airflow.

Purple fountain grass is typically carefree in the yard as long as the plant is located in a sunny spot.

The grass is treated as an annual in zones where temperatures drop to 20 degrees Fahrenheit, but the plant should last several seasons in warmer climates where it is considered a perennial, though a somewhat short-lived one.

Though it’s usually grown outdoors, purple fountain grass can also grow well indoors as a houseplant if given cool and sunny conditions.

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1. Snails and Slugs. University of California Agriculture and Natural Resources.
2. Ornamental Grasses. Missouri Botanical Garden.